There is a direct correlation between the affluence and industrialization of a society and the quantity of refuse which is generated by that society. Thus, in the industrialized nations, the quantity of refuse which is generated may be many times that generated in a more primitive society.
In modern refuse collection apparatus, the refuse is compacted within a pressurized storage container. The storage container may, for example, be mounted on the frame of a truck with the tailgate rotatably secured to the rear of the container. Within the tailgate, there is generally a packing mechanism, with refuse being placed in a loading hopper in the tailgate and the packing mechanism forcing the refuse under high pressures into the storage container. By forcing the refuse into the storage container under high pressures, the refuse is compacted so that a relatively large quantity of refuse may be carried within the storage container. This permits the refuse collection apparatus to function for a long period of time before it becomes necessary to empty the storage container. The time spent in driving to a landfill or refuse transfer point to empty the storage container is time lost from the primary function of the apparatus in picking up the refuse at a home or a business and placing the refuse in a compacted form which is convenient for its disposal. Accordingly, it is essential to the function of a refuse collection apparatus that the quantity of refuse carried within the refuse container be maximized.
To maximize the quantity of refuse which may be packed under pressure within the refuse storage container, it has previously been necessary to construct the apparatus of heavy structural members to provide great strength. This has resulted in the refuse compaction apparatus being relatively large and heavy. These requirements have increased the costs of refuse compaction apparatus and have made the apparatus a high consumer of energy for operation. Additionally, the weight of previous refuse collection apparatus may be injurious to street surfaces over which the apparatus is driven.
In addition to being relatively heavy and expensive, previous refuse collection apparatus has been relatively complicated. In previous apparatus, it has generally been necessary to place hydraulic cylinders on either side of the tailgate to drive the packing mechanism in forcing the refuse from the loading hopper into the refuse storage container. The weight and expense of the hydraulic cylinders have, thus, contributed to the overall weight and expense of the refuse collection apparatus. Additionally, to control a plurality of hydraulic cylinders to insure that the driving forces applied to each end of the packing mechanism are synchronized has required the use of complex hydraulic circuitry. This may reduce the reliability of the refuse collection apparatus, since the reliability of a complex mechanism is generally inversely proportional to the complexity of the mechanism.
In view of the above problems, it would be desirable if a refuse compaction apparatus could be provided which would be lighter than previous apparatus and which would consume a smaller quantity of energy for operation. Such an apparatus would also be cheaper because of the use of lighter and less expensive structural members used in its construction. These would be considerable advantages in view of the ever-increasing cost of energy in the form of oil, gasoline and other fossil fuels for operation of industrial equipment. Additionally, by being lighter than previous collection apparatus, such an apparatus would be less injurious to the public streets in its operation.
In addition to providing a refuse compaction apparatus which would be cheaper and lighter, it would be desirable to provide an apparatus which would be simpler in its construction, and, therefore, more reliable and less likely to break down. Desirably, such an apparatus would provide a mechanical interconnection between the hydraulic motors used to drive the packing mechanism. This would serve to eliminate the previous problems of synchronizing the movement of hydraulic cylinders to drive the packing mechanism by means of a complex hydraulic circuit. Also, it would be desirable if such a refuse compaction apparatus could function by driving the packing mechanism from only one end, since this would tend to avoid the many problems which may result from the use of duplicate drive cylinders positioned at either end of the packing mechanism, which cylinders must be synchronized in their movements.
In addition, it would be desirable if a refuse compaction apparatus could be provided in which the refuse could be subjected to very high pressures before being placed within the refuse storage container. This would permit the retention of highly compacted refuse within the storage container at reduced pressures. The storage container could then be made lighter while still performing its function of containing a maximum quantity of refuse to reduce the amount of lost time required to periodically empty the container.